<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">

  <title>lable</title>
  <script src="vue/vue.js"></script>
</head>
<style>
  .asd{
    display: none;
  }
</style>
<body>
<div id="ass">
<div v-bind:class="{asd:a}">nihao1</div>
  <div v-bind:class="{asd:b}">nihao2</div>
</div>
<script>
  var sdas=new Vue({
    el: '#ass',
    data:{
      a:true,
      b:false
    }
  })
</script>
</body>
</html>